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Old 11-20-2012, 08:12 PM   #20
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NOTICE: This thread was started to only show that it is possible to have RAID0 trim with some currently unsupported chipsets. I never have worked in the computer/software industry and all testing done is purely empirically based and therefore prone to error. To get proper RAID0 trim support wait for Intel and manufacturers to provide an updated OROM with validation to ensure proper operation.

The 11.6 OROM appears to have a look up table.

It seems the first word lists the RAID controller Alternate ID (AI) to identify the controller, the second word lists the LPC ID to identify sub groups that utilize the RAID controller and a byte follows to indicate set flags.

For instance alternate ID 1C05 (8086:1C05) is a 6 series mobile RAID controller. This has two LPC sub groups, 1C4B (HM67) and 1C4F (QM67). Bit 0 of the flag byte is set to 1 which I think means SRT support. Where the LPC ID is 0000 I guess this means all sub groups. Alternate ID 1C05 is for the Z68 which has only bit 0 set in the flag byte, meaning support for SRT but not trim. Alternate ID's are a way of identifying controllers that normally use a common ID, i.e. 2822 (8086:2822).

Now you can hopefully see why it appears Intel have made it easy to add other chipsets, they just need to be added to the LUT. For testing however I just overwrote one of the ones in the list. For the P67 which has an alternate ID of 1C04 I simply used "1C04 0000 07" and like wise for the P55 which has an alternate ID of 3B25 I used "3B25 0000 07".

I notice my BIOS for the P67 does not enable SRT in the feature settings so I might have another look at that when I get time, which I seem to have very little of at the moment. Also the Asrock X79 Extreme11 BIOS 1.70 does provide for the RST 11.6 OROM (2822) to be selected in the BIOS setup instead of the RSTe 3.5 OROM (2826) so with the alternate ID 1D04 & 1D06 already in the 11.6 OROM and with the flag byte set to 07 I would have expected not only SRT to work but trim also but one user reports trying it and no trim. Possibly due to broken SSD firmware.

Remember that trim is an enhancement, IMHO with a fair amount of user over provisioning it should not matter too much if it's not available, that is if you are able to set aside some unused disk space for this. For instance by creating the RAID0 volume size smaller than the combined disk size.

Last edited by Dufus; 11-25-2012 at 04:20 AM. Reason: X79 failure may have been due to broken trim in SSD firmware.
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